1. Field of the Invention
This invention relates to new, antibacterial 1-oxadethiacephalosporin derivatives exhibiting high "in vitro" and "in vivo" antibacterial activity, particularly against the .beta.-lactamase-producing bacteria. This invention also relates to a process for the production of the new 1-oxadethiacepharosporin derivatives. This invention further relates to antibacterial composition containing said 1-oxadethiacephalosporin derivatives as well as to the chemotherapeutic use of these 1-oxadethiacephalosporins and the pharmaceutically acceptable salts and esters thereof.
2. Description of the Prior Art
Many, various derivatives of cephalosporin have been produced and used in therapeutic treatment of bacterial infections. In the recent years, various derivatives of 1-oxadethiacephalosporin have been produced synthetically and proposed to be used for in therapeutic treatment of bacterial infections (see, for example, U.S. Pat. Nos. 4,011,216; 4,013,648; 4,013,653; 4,031,083; 4,045,438; 4,138,486 and 4,180,571). We have researched extensively in an attempt to provide new further derivatives of 1-oxadethiacephalosporin having high and broad antibacterial activity against gram-positive and gram-negative bacteria and even against the .beta.-lactamase-producing strains which are usually resistant to the known cephalosporins. As a result of our studies, we have now succeeded to synthetize new derivatives of 1-oxadethiacephalosporin, and we have found that these new derivatives of 1-oxadethiacephalosporin now synthetized have more excellent antibacterial properties than those of the known cephalosporin derivatives.